A pressure cooker cooks a lot faster than an ordinary pan by maintaining a higher pressure and temperature inside. The lid of a pressure cooker is well sealed, and steam can escape only through an opening in the middle of the lid. A separate metal piece, the petcock, sits on top of this opening and prevents steam from escaping until the pressure force overcomes the weight of the petcock. The periodic escape of the steam in this manner prevents any potentially dangerous pressure buildup and keeps the pressure inside at a constant value. Determine the mass of the petcock of a pressure cooker whose operation pressure is 100 kPa gage and has an opening crosssectional area of 4 mm2. Assume an atmospheric pressure of 101 kPa, and draw the freebody diagram of the petcock.
Latent heat and phase change
A physical process in which a conversion among the basic states or phases of matter, i.e., solid, liquid, and gas takes place under the effect of a certain temperature and pressure is referred to as a phase change. Generally, the phase change of a substance occurs when heat transfer takes place between the substance and its surroundings. Based on the direction in which heat transfer takes place, different types of phase changes can occur.
Triple Point of Water
The branch of physics in which observer deals with temperature related properties is called thermodynamics.
Boiling Point of Water
Everyday examples of boiling is, boiling milk, heating water. One would have observed that when we heat water it goes through various stages and at one point bubbles show in water, and water keeps splashing with bubbles bursting, we in layman terms say that water is boiling.
Freezing Point of Water
In general, the freezing point of water is 0° Celsius, or 32° Fahrenheit. This is the temperature at which water will ordinarily change from its liquid state to its solid state (ice). However, there are certain conditions that can affect the freezing point of water. For example, a liquid may be supercooled or contain impurities so that it does not freeze at the ordinary freezing point.
A pressure cooker cooks a lot faster than an ordinary
pan by maintaining a higher pressure and temperature inside.
The lid of a pressure cooker is well sealed, and steam can
escape only through an opening in the middle of the lid. A
separate metal piece, the petcock, sits on top of this opening
and prevents steam from escaping until the pressure force
overcomes the weight of the petcock. The periodic escape
of the steam in this manner prevents any potentially dangerous
pressure buildup and keeps the pressure inside at a constant
value. Determine the mass of the petcock of a pressure
cooker whose operation pressure is 100 kPa gage and has
an opening crosssectional
area of 4 mm2. Assume an atmospheric
pressure of 101 kPa, and draw the freebody
diagram
of the petcock.
Trending now
This is a popular solution!
Step by step
Solved in 3 steps with 3 images
